/*
* ==============================================================================
*  Name        : AudioStreamEngine.h
*  Part of     : AudioStream
*  Created     : April 28, 2006 by Forum Nokia
*  Description : Declares the Engine class for AudioStream application
*  Version     : 2.0
*
*  Copyright (c) 2006 - 2007 Nokia Corporation.
*  This material, including documentation and any related
*  computer programs, is protected by copyright controlled by
*  Nokia Corporation.
* ==============================================================================
*/

#ifndef AUDIOSTREAMENGINE_H
#define AUDIOSTREAMENGINE_H

// INCLUDES
#include <e32base.h>
#include <aknviewappui.h> 

#include <mda\common\audio.h>
#include <MdaAudioInputStream.h>	// audio input stream
#include <MdaAudioOutputStream.h>	// audio output stream

#include "AudioStream.hrh"
#include "AudioStreamView.h"	
#include "AudioStreamAppUi.h"	

// FORWARD DECLARATIONS
class CAudioStreamView;

// CLASS DECLARATION

/**
*  CAudioStreamEngine application engine class.
*  
*/
class CAudioStreamEngine : public CBase, MMdaAudioInputStreamCallback, 
	MMdaAudioOutputStreamCallback
{
public:
/*!
 * NewL()
 * 
 * discussion Create new CAudioStreamEngine object
 * return a pointer to the created instance of CAudioStreamEngine
 */
    static CAudioStreamEngine* NewL(CAudioStreamAppUi* /* aAppUi */);

/*!
 * NewLC()
 * 
 * discussion Create new CAudioStreamEngine object
 * return a pointer to the created instance of CAudioStreamEngine which 
 *    has also been pushed to cleanup stack
 */
    static CAudioStreamEngine* NewLC(CAudioStreamAppUi* /* aAppUi */);


/*!
 * ~CAudioStreamEngine()
 *
 * discussion Destroy the object and release all memory objects
 */
	~CAudioStreamEngine();
        

public: // New functions
	
/*!
 * Play()
 *
 * discussion Plays the audio data sample
 */
	void Play();
/*!
 * Record()
 *
 * discussion Records an audio data sample
 */
	void Record();
/*!
 * Stop()
 *
 * discussion Stops the playing/recording of the audio data
 */
	void Stop();
	
/*!
 * LoadAudioFileL()
 *
 * discussion Loads an audio data from a file
 */
	void LoadAudioFileL();
/*!
 * SaveAudioFileL()
 *
 * discussion Saves the audio data into a file
 */
	void SaveAudioFileL();

/*!
 * SetEncodingL()
 *
 * discussion Sets the audio encoding to be used
 * param aAmr If ETrue, AMR-NB encoding will be used, if EFalse, the platform's
 * default encoding will be used
 */
	void SetEncodingL(TBool aAmr);
	
private: // in-class methods

/*!
 * GetFrame()
 *
 * discussion Returns a modifiable pointer to a single frame inside the
 * audio buffer
 *
 * param aFrameIdx frame index
 * return a TPtr8 reference to the requested frame
 */
	TPtr8& CAudioStreamEngine::GetFrame(TUint aFrameIdx);
/*!
 * GetPlaybackFrames()
 *
 * discussion Returns a modifiable pointer to frames from the first frame to 
 * aLastFrame in the audio buffer
 *
 * param aLastFrame Index of the last frame to be included in the pointer returned
 * return a TPtr8 reference to the requested frames
 */
	TPtr8& CAudioStreamEngine::GetPlaybackFrames(TUint aLastFrame);

/*!
 * ShowMessage()
 *
 * discussion Displays application messages for user on a label
 *
 * param aMsg text to be displayed
 * param aReset if true, the label will be cleared before displaying aMsg,
 *    if false, aMsg text will be appended to existing message on label
 */
	void ShowMessage(const TDesC& /* aMsg */, TBool /* aReset=false */);
	
/*!
 * MaiscOpenComplete()
 *
 * discussion A callback function that is called when 
 *    CMdaAudioInputStream::Open() has completed, indicating that the audio 
 *    input stream is ready for use.
 *
 * param aError KErrNone if the open succeeded, otherwise one of the system 
 *    error codes.
 */
	virtual void MaiscOpenComplete(TInt aError);
/*!
 * MaiscBufferCopied()
 *
 * discussion A callback function that is called when a chunk of audio data 
 *    has been copied to the descriptor specified in a 
 *    CMdaAudioInputStream::ReadL().
 *
 * param aError KErrNone if the copy succeeded, KErrAbort if the input stream
 *    was closed for some reason, otherwise one of the system error codes.
 */
	virtual void MaiscBufferCopied(TInt aError, const TDesC8& aBuffer);
/*!
 * MaiscRecordComplete()
 *
 * discussion A callback function that is called when the input stream is
 *    closed using CMdaAudioInputStream::Stop(). 
 *
 * param aError KErrNone if the stop succeeded, otherwise one of the system
 *    error codes.
 */	
	virtual void MaiscRecordComplete(TInt aError);

/*!
 * MaoscOpenComplete()
 *
 * discussion A callback function that is called when 
 *    CMdaAudioOutputStream::Open() has completed, indicating that the audio 
 *    output stream is ready for use.
 *
 * param aError KErrNone if the open succeeded, otherwise one of the system 
 *    error codes.
 */
	virtual void MaoscOpenComplete(TInt aError);
/*!
 * MaoscBufferCopied()
 *
 * discussion A callback function that is called when a descriptor has been 
 *    copied to the lower layers of MMF. It is also called when an error has 
 *    occurred or when the client has stopped the stream playing before the 
 *    descriptor has been fully copied (by calling 
 *    CMdaAudioOutputStream::Stop())
 *
 * param aError KErrNone if the copy succeeded, otherwise one of the system
 *    error codes. KErrAbort indicates that the client has stopped the stream
 *    playing before the descriptor has been copied.
 * param aBuffer reference to the buffer that has been copied.
 */
	virtual void MaoscBufferCopied(TInt aError, const TDesC8& aBuffer);
	
/*!
 * MaoscPlayComplete()
 *
 * discussion A callback function that is called when playback terminates as
 *    a result of a CMdaAudioOutputStream::Stop().
 *
 * param aError KErrNone if the close succeeded, otherwise one of the system
 *    error codes.
 */
	virtual void MaoscPlayComplete(TInt aError);

public: // Functions from base classes

private: // Basic two-phase EPOC constructors

/*!
 * ConstructL()
 *
 * discussion Perform the second phase construction of a CAudioStreamEngine 
 *    object
 */
    void ConstructL();
 
/*!
 * CAudioStreamEngine()
 *
 * discussion Perform the first phase of two phase construction 
 */
    CAudioStreamEngine(CAudioStreamAppUi* /* aAppUi */);

private:	

	// enumeration of input/output stream status
	enum TStatus
		{
		ENotReady,
		EOpen
		};

		
private: 	// data members

	// application UI object reference
	CAudioStreamAppUi* iAppUi;
	// audio input stream object reference
	CMdaAudioInputStream* iInputStream;
	// audio output stream object reference
	CMdaAudioOutputStream* iOutputStream;

	// Handle to CCoeEnv's file server
	RFs iFs;

	// Do we use AMR-NB encoding?
	TBool iUseAMR;
	// The path to the sample audio file (sample.aud or sample.amr)
	TFileName iAudioFilePath;
	// The audio file to be used (sample.aud or sample.amr)
	TFileName iAudioFile;	
	// The frame size for the current encoding
	TUint iFrameSize;
	// The number of frames to be buffered
	TUint iFrameCount;

	// A buffer containing the audio frames
	HBufC8* iStreamBuffer;	
	// Modifiable pointer used to reference a single frame in iStreamBuffer 
	// while recording, and all the valid frames in iStreamBuffer while playback (the
	// iStreamBuffer might not always be fully recorded in this example).
	TPtr8 iFramePtr;
	// Buffer status (does it contain valid audio data)
	TBool iBufferOK;
	// The default encoding used by the platform
	TFourCC iDefaultEncoding;
	// The encoding we are currently using
	TFourCC iCurrentEncoding;

	// Audio data stream settings for input and output streams
	TMdaAudioDataSettings iStreamSettings;
	// Status enumeration of input stream
	TStatus iInputStatus;
	// Status enumeration of output stream	
	TStatus iOutputStatus;
	// Index of audio data block currently being played/recorded on the buffer
	TUint iStreamIdx;
	// Application status message displayed to user
	TBuf<255> iMsg;
	// Stream start (first audio block in buffer) and end index
	TUint iStreamStart;
	TUint iStreamEnd;
	
};

#endif // AUDIOSTREAMENGINE_H


